How can I get the top path of glob path?

Question

e.g.

a/b/c* -> a/b
a/b/c*/*/*b -> a/b

Why I need this is because I want to get the abs path of globed filename. Code example:

files, _ := filepath.Glob(p)
top := __magic here__
for _, f := range files {
    abs, _ := filepath.Abs(path.Join(top, f))
    fmt.Println(abs)
}

Is there any exists method for this purpose? otherwise I have to implement by myself.

EDIT

The magic is make glob path abs first, then the glob return abs path.

Answer 1

File names returned by filepath.Glob() are already absolute (but read below).

See this example:

fs, err := filepath.Glob("/dev/../dev/*")
if err != nil {
    panic(err)
}
for _, f := range fs {
    fmt.Println(f, filepath.IsAbs(f))
}

Output:

/dev/null true
/dev/random true
/dev/urandom true
/dev/zero true

Try it on the Go Playground.

Edit:

The returned file names are only absolute if the glob pattern is absolute. So the easiest way is to make the glob pattern absolute.